Pio vs suppositories

So, I saw my fertility specialist today and we reviewed my protocol for my April/May FET. (Transferring 1 embryo)

I had a successful FET in November of 2016 and gave birth to my daughter on my due date in August 2017. My protocol for that cycle (we transferred 2 embryos) was estrace 2x daily and progesterone (endometrum) 3x daily until week 10 of pregnancy both vaginal suppository. Well after my sonohysterogram today which all looked great, my dr said since my last FET newer research is showing pio shots show higher success rates in fets. We have 4 embryos left of AB grade day 6 blastocysts so I’m feeling like we must have 1 more baby for us in there, however I’m wondering what you all have been told or what your protocols were? I’m not opposed to pio shots at all and will do whatever my drs think I should but this was new news so I figured I would reach out, I hated the suppositories and it was annoying to remember them 3x a day so maybe a shot a day would be easier?! Drs said since I had success with endometrum I could choose to go that way if I wanted ... but transferring 1 embryos at a time I’m leaning towards pio

Thanks all!